How To Control The Lights With A TV Remote

February 16, 2018 by Lewin Day 16 Comments

In this day and age of the Internet of Things and controlling appliances over the internet, the idea of using an old-fashioned television remote to do anything feels distinctly 2005. That doesn’t mean it’s not a valid way to control the lights at home, and [Atakan] is here to show us how it’s done.

To the experienced electronics maker, this is yesterday’s jam, but [Atakan] goes to great lengths to hash out the whole process from start to finish, from building the circuitry to switch the lights through to the code necessary to make a PIC do your bidding. It’s rare to see such a project done with a non-Arduino platform, but rest assured, such things do exist. There’s even some SPICE simulation thrown in for good measure, if you really want to get down to the nitty-gritty.

Perhaps the only thing missing from the writeup is a primer on how to execute the project safely, given that it’s used with a direct connection to live mains wiring. We’d love to hear in the comments about any changes or modifications that would be necessary to ensure this project doesn’t hurt anyone or burn an apartment complex down. Sometimes you can switch lights without a direct connection to the mains, however – like this project that interfaces mechanically with a standard light switch.

The UA723 As A Switch Mode Regulator

February 15, 2018 by Jenny List 37 Comments

If you are an electronic engineer or received an education in electronics that went beyond the very basics, there is a good chance that you will be familiar with the Fairchild μA723. This chip designed by the legendary Bob Widlar and released in 1967 is a kit-of-parts for building all sorts of voltage regulators. Aside from being a very useful device, it may owe some of its long life to appearing as a teaching example in Paul Horowitz and Winfield Hill’s seminal text, The Art Of Electronics. It’s a favourite chip of mine, and I have written about it extensively both on these pages and elsewhere.

The Fairchild switching regulator circuit. From the μA723 data sheet in their 1973 linear IC databook, page 194 onwards.

For all my experimenting with a μA723 over the decades there is one intriguing circuit on its data sheet that I have never had the opportunity to build. Figure 9 on the original Fairchild data sheet is a switching regulator, a buck converter using a pair of PNP transistors along with the diode and inductor you would expect. Its performance will almost certainly be eclipsed by a multitude of more recent dedicated converter chips, but it remains the one μA723 circuit I have never built. Clearly something must be done to rectify this situation.

Continue reading “The UA723 As A Switch Mode Regulator” →

This IS Your Grandfather’s Radio

February 14, 2018 by Al Williams 9 Comments

Tube radios have a certain charm. Waiting for them to warm up, that glow of the filaments in a dark room. Tubes ruled radio for many decades. [Uniservo] posted a video about the history and technology behind the 1920’s era Clapp-Eastham C-3 radio. This is a three-tube regenerative receiver and was advanced for its day.

If you are worried he won’t open it up, don’t despair. Around the ten minute mark, your patience will be rewarded. Inside are three big tubes full of getter and bus bars instead of wires. Add to that the furniture-quality case, and this is a grand old radio.

Continue reading “This IS Your Grandfather’s Radio” →

AT-ST High Chair Elevates Lucky Jedi Youngling

February 14, 2018 by Tom Nardi 20 Comments

As a new parent, there’s lots you have to do. You have to buy a car seat, get the baby’s room ready, figure out daycare; all the boring but unavoidable minutiae of shepherding a tiny human. But for the more creative types, that list might include warming up the 3D printer or putting a fresh bit in the CNC, as there’s no better way to welcome a little one into the world than giving them some custom gear to get started with.

That’s certainly been the plan for [Matthew Regonini], who’s been showering his son with DIY playthings. He recently wrote in to tell us about his awesome AT-ST high chair build that manages to turn the drudgery of getting a baby to eat into an epic worthy of a John Williams score.

This isn’t the first time [Matthew] has turned dead trees into Imperial hardware. Last year we covered his fantastic AT-AT rocker which utilized the same construction techniques. The parts are cut out of plywood with his CNC, separated, cleaned up on a spindle sander, and finally assembled with wood glue and a few strategic fasteners. The depth and level of detail he’s able to achieve when the individual pieces are stacked up is exceptionally impressive. If builds like these don’t get you thinking about adding a CNC to your workshop, nothing will.

As with the AT-AT, the finish on the high chair is simply a healthy application of polyurethane. This keeps the wood from being porous (important as this build will be seeing its fair share of food and liquids) while retaining a natural look. Some might be tempted to paint it up in appropriate Imperial colors, but that might be a bit imposing considering its intended occupant.

Really, the only downside with this build is how quickly his son will outgrow it. The obvious solution to the problem is a constant supply of fresh babies to pilot it, but that’s one type of creation that we don’t generally detail here on Hackaday. If you have questions, ask your parents.

Incidentally, it’s starting to look like we’ve got a plywood arms-race going on. We’re excited to see somebody take it to the next level. A little scared, but mainly excited.

Continue reading “AT-ST High Chair Elevates Lucky Jedi Youngling” →

Flood Damaged 386 Gets A Modern Rebuild

February 11, 2018 by Tom Nardi 28 Comments

Until a flood claimed its life, the 386 tower [Tylinol] found on the side of the road served him well as a DOS gaming rig. In the aftermath of the flood, the machine was left with ruined internals and a rusted case; it ended up being tossed in storage where it was slowly rotting away. But a recent idea got him to drag this old dinosaur back out into the light of day and give it a new lease on life with some modern gear.

For our viewing pleasure [Tylinol] documented the restoration of the computer, dubbed SErEndIPITy, from start to finish. The rebuild starts with tearing the machine down to the steel frame and sanding all the rust off. Luckily it looks like no structural damage was done, and a coat of engine enamel got the frame looking more or less like new. The original motherboard mounting solution wouldn’t work for his modern board, so he ended up riveting a piece of sheet metal in and drilling new holes for standoffs to thread into.

A nice element of this rebuild is that [Tylinol] didn’t want to drastically change the outward appearance of the machine. The customary yellowed plastic was left alone, and wherever possible the original hardware was reused. Rather than blow a hole in the case, he took his Dremel to the decorative ribbed design of the front panel and turned it into a stock-looking vent.

The real star of this rebuild is the LED CPU “Speed” display on the front of the case. In its original form, this was a fake display that simply cycled through predefined digits when you pressed the “Turbo” button on the front panel. By grounding them one at a time, [Tylinol] figured out which lines on the PCB controlled each segment of the display and wired it up to a Teensy 3.5. He was then able to write a C# plugin for CoreTemp to display the temperature.

The rebuilt machine is packing an i5-6500 processor, GTX 970 video card, and 8 GB of DDR4 RAM. Not exactly a speed demon compared to some of the modern desktops out there, but it certainly beats the original hardware. Incidentally, so does the Teensy 3.5 controlling the front panel display. There’s a certain irony there…

Cramming modern hardware into the carcass of an outdated computer is nothing new, of course. But we especially like the builds that take the time to make it all look stock.

[via /r/DIY]

Membership Ring Of The Electronic Illuminati

February 10, 2018 by Mike Szczys 21 Comments

When the cabal of electronic design gurus that pull the invisible strings of the hardware world get together, we imagine they have to show this ring to prove their identity. This is the work of [Zach Fredin], and you’re going to be shocked by the construction and execution of what he calls Cyborg Ring.

The most obvious feature of the Cyborg Ring is the collection of addressable LEDs that occupy the area where gems would be found on a ring. What might not be so obvious is that this is constructed completely of electronic components, and doesn’t use any traditional mechanical parts like standoffs. Quite literally, the surface mount devices are structural in this ring.

They are also electrical. Here you can see a detail of how [Zach] pulled this off. We are looking at the underside of the ring, the part that goes below your knuckle. One of the two PCBs that are sized to fit your finger has been placed in a Stick Vise while the QFN processor is soldered on end, and the pairs of SMD resistors are put in place.

The precise measurements of each part make it possible to choose components that will perfectly span the gap between the two boards. In the background of the image you can see SMD resistors on their long ends — a technique he used to allow the LEDs themselves to span between one resistor on each of the two PDBs to complete the circuit. Incredible, right?

But it gets better. [Zach] ended up with a working prototype, but has continued to forge ahead with new design iterations. These updates are a delight to read! Make sure you follow his project and check in regularly; if you’ve already looked at this now’s the time to go back and see the new work. The gold pads for the minuscule coin cells which power the ring are being reselected as the batteries didn’t fit well on the original. Some layout problems are being tweaked. And the new spin of boards should be back from fab in a week or so.

Don’t miss the demo video found below. We really like seeing projects that build within the wearble ring form factor. It’s an impressive constraint which [Zach] seems to have mastered. Another favorite of ours is [Kevin’s] Arduboy ring.

Continue reading “Membership Ring Of The Electronic Illuminati” →

Ride Bike, Charge Phone

February 8, 2018 by Kristina Panos 49 Comments

Spring is coming to the northern hemisphere, and soon it’ll be nice enough outside to tool around town on your bicycle. But bikes don’t have power outlets, so phone charging on the go will require forethought and charged-up battery packs. It doesn’t have to be that way. You’re working to make the bike move, so why not make the bike work for you?

If you’ve ever used a motor as a generator, then you can see where this is going. That’s the underlying principle behind [Creativity Buzz]’s bike-powered phone charger. As the bike wheel turns, the rim comes in contact with a small wheel attached to the output shaft of a DC motor. Cranking the output shaft of a motor with permanent magnets inside will induce a small voltage, and here it is amplified with a DC-DC boost converter and output to a USB jack.

As long as you can find a way to secure the phone to the bike frame, or use a long cord and good cable management, you’re in business. Wheelie past the break to watch [Creativity Buzz] build it and give it a stationary test run. While you wait for bike-riding weather, you can still use this kind of charger by turning a crank.

Continue reading “Ride Bike, Charge Phone” →